Page 14 - Multifunctional Photocatalytic Materials for Energy

Introduction 3

cells (QDSCs), PSCs, and OSCs are covered in overview. The authors categorize metal
oxide-based semiconductor layers into two groups according to their unique features:
semiconductor nanomaterials as interfacial materials for solar cells, and semiconductor
nanomaterials as mesoporous layers for solar cells. Then, the chapter focuses on fabri-
cation methods for preparing efficient nanostructured photoanodes, the application of
these nanostructured photoanode materials and their impact on device efficiency, and
the roles of different interfacial layers used in improving the output of these devices.
In Chapter 9 by Marotta Raffaele et al., metal-based semiconductor nanomaterials
for photocatalysis are comprehensively reviewed. The text first introduces the funda-
mentals of photocatalytic water splitting and organic photo-reforming, followed by
a discussion of metal-based semiconductor nanomaterials (i.e., metal oxides, metal
sulfides, and metal nitrides, etc.) used as photocatalysts for hydrogen production. In
particular, recent strategies for improving the effectiveness of the most common metal-
based semiconductors are highlighted as well. Finally, the chapter discusses the main
experimental factors involving performance and design of photocatalytic materials.
Chapter 10 by Bhaghavathi Parambath Vinayan et al., is especially concerned with
recent progress regarding conjugated polymer and nanocrystal nanocomposites for
photocatalytic hydrogen production and organic contaminant degradation. The fun-
damentals of inorganic/organic semiconductors are indicated first. Introduction of
nanocrystals and nanocomposites including synthesis routes, optical and electronic
properties, physical/chemical characterization, and work mechanism of photocatalysis
are comprehensively discussed. Based on these catalysts, the performance of hydro-
gen evolution and organic contaminant degradation is shown.
In Chapter 11 by Yuekun Lai et al., the authors concentrate on nanostructured TiO 2
catalysts for hydrogen generation. Multi-dimensional TiO 2 nanostructures, from 0D
nanoparticles, 1D nanotubes, nanowires, nanorods, and 2D nanosheets, to 3D hollow
and hierarchical nanostructures, are elaborately introduced one by one. Then, solar
water splitting based on these TiO 2 nanostructured materials is discussed. Insight into
critical engineering strategies for high-performance TiO 2 nanocatalysts is emphasized,
such as increasing the active areas of the surface, enhancing visible light absorption,
and reducing the recombinant properties of electron-hole pairs.
Chapter 12 by Kazuhiko Maeda et al., covers hybrid Z-scheme nanocomposites for
photocatalysis. Photocatalytic CO 2 reduction using metal complexes and semiconduc-
tors is presented. Metal complexes and semiconductor-based systems, as well as their
hybrid systems, are introduced one by one. Molecular-based photocathodes coupled
with semiconductor photoanodes, and semiconductor electrodes modified with a metal
complex catalyst used in photoelectrochemical CO 2 reduction are discussed in detail.
In Chapter 13 by A. Chithambararaj et al., ferroelectric materials with regards to
photocatalytic areas are addressed. Fundamentals and materials (e.g., titanates, nio-
bates, and tantalates) of ferroelectric photocatalysts are first shown. Then, synthesis
and characterizations of ferroelectric photocatalysts are subsequently summarized.
Theoretical and computation methods proposed for ferroelectric photocatalysts are
provided as well. Architectural design of ferroelectric photocatalysts is also empha-
sized. Factors (e.g., crystal structure, morphology, crystal size, and pH) involved in
ferroelectric-based photocatalytic reactions are elaborately discussed.